ABSTRACT
SARS-CoV-2 has very recently posed a potential threat to humanity due to its very rapid rate of mutations and repairing mechanism. The spread of this virus is considered to have occurred in Wuhan, China in December 2019. Characterized by high rates of transmission, the virus is constantly evolving towards attaining higher rates of stability and transmissibility through acquiring mutations in its genome. Therefore, this study aims to analyse the mutational profiles of SARS-CoV-2 isolates. Analysis of the mutational profiles in individual SARS-CoV-2 proteins will allow us to look into the rates of mutations associated with each protein. Frequently mutated residues have been identified in this research by aligning 688 SARS-CoV-2 nucleotide sequences, which were downloaded from NCBI (National Center For Biotechnology Information) repository. Further, mutational frequencies of these mutated residues have been studied, which is instrumental in identifying the proteins that are resistant to changes, as well as the ones that have a greater proclivity towards incorporating mutations. © 2022, Walailak University. All rights reserved.
ABSTRACT
SARS-CoV-2 is mutating and creating divergent variants by altering the composition of essential constituent proteins. Pharmacologically, it is crucial to understand the diverse mechanism of mutations for stable vaccine or anti-viral drug design. Our current study concentrates on all the constituent proteins of 469 SARS-CoV-2 genome samples, derived from Indian patients. However, the study may easily be extended to the samples across the globe. We perform clustering analysis towards identifying unique variants in each of the SARS-CoV-2 proteins. A total of 536 mutated positions within the coding regions of SARS-CoV-2 proteins are detected among the identified variants from Indian isolates. We quantify mutations by focusing on the unique variants of each SARS-CoV-2 protein. We report the average number of mutation per variant, percentage of mutated positions, synonymous and non-synonymous mutations, mutations occurring in three codon positions and so on. Our study reveals the most susceptible six (06) proteins, which are ORF1ab, Spike (S), Nucleocapsid (N), ORF3a, ORF7a, and ORF8. Several non-synonymous substitutions are observed to be unique in different SARS-CoV-2 proteins. A total of 57 possible deleterious amino acid substitutions are predicted, which may impact on the protein functions. Several mutations show a large decrease in protein stability and are observed in putative functional domains of the proteins that might have some role in disease pathogenesis. We observe a good number of physicochemical property change during above deleterious substitutions.
ABSTRACT
In the NCBI database, as on June 6, 2020, total number of available complete genome sequences of SARS-CoV2 across the world is 3617. The envelope (E) protein of SARS-CoV2 possesses several non-synonymous mutations over the transmembrane and C-terminus domains in 15 (0.414%) genomes among 3617 SARS-CoV2 genomes, analyzed. More precisely, 10(0.386%) out of 2588 genomes from the USA, 3(0.806%) from Asia, 1 (0.348%) from Europe and 1 (0.274%) from Oceania contained the missense mutations over the E-protein of SARS-CoV2 genomes. The C-terminus motif DLLV has been to DFLV and YLLV in the proteins from QJR88103 (Australia: Victoria) and QKI36831 (China: Guangzhou) respectively, which might affect the binding of this motif with the host protein PALS1.